Stylesheet randomly won't load.

The worst part about this problem is that there’s no obvious cause and I don’t even know what it is to properly explain it.

I have had WordPress integrated into my site for years. Despite not using it much, I log on often and upgrade whenever necessary. This particular layout I have has been up for about 2 years and I’ve never had a problem.

Last night I visited my site and was screwing around, refreshing the pages…just trying to think of new things to write about or maybe new design ideas (note: I never ONCE edited the actual theme), and after one refresh too many, the blog just stopped displaying properly.
I think the best way to describe it is black letters on a black background with default-blue links. It was as if the stylesheet itself just wouldn’t load.
I checked my site’s NON-WORDPRESS pages (because it uses almost-identical CSS), and they load absolutely fine. So based on that, I’m sure it has something to do with WordPress and not my own server/host.

I FINALLY found a quick fix: opened up the Theme Editor and (without adding or altering a thing) just hit the “update” button.
After doing that, the page loaded as it should.

But today, as I was typing a new entry, the same thing happened. The “preview” option was working fine, and then just suddenly started displaying a tacky white page with default colors/fonts and no sidebar.
When I exited out of the WordPress Dashboard and tried to load my site as a regular visitor, the WordPress layout was still not loading.
Again, it was fixed by opening the Theme Editor and just simply hitting “update”, without actually changing a thing.

So the layout-loading problem seems to just be triggered after XX amount of visits/pageloads.

I don’t understand how this is possible… if anybody has any clue what the problem might be, please help!

Here is a link to the blog: https://sodapopink.com/blog
As of one minute ago, it is loading properly. Background should be black and entries should be in a pale-green table with rounded corners.